“As” is not a co-ordinating conjunction.
It does not join two independent clauses of equal weight.
It does not link actions that happen in sequence.
It is a subordinating conjunction, and it links a primary action to a secondary action that takes place at the same time as the primary action.
So for Pete’s sake, don’t commit sentences like this one:
“I think this is the main road,” said Joe, as he surveyed the landscape around them, as he stood next to Jane.
Break it down into its components:
- Joe said, “I think this is the main road.”
- Joe surveyed the landscape around them.
- Joe stood next to Jane.
Then decide which parts are primary and which are secondary, and rewrite your paragraph accordingly:
Joe stood next to Jane and surveyed the landscape around them. “I think this is the main road,” he said.
Or, if you decide that the fact he’s standing next to Jane is more important in the overall scheme of things than the fact that he’s looking around, you could write it this way:
Joe stood next to Jane as he surveyed the landscape around them. “I think this is the main road,” he said.
Don’t just string your clauses together any which way. Think about their relative weight and importance first. This will make your sentences a lot less monotonous; as a side benefit, it will also make your writing clearer and more effective.